With the widespread use of portable electronics such as high-quality smart phones, Pads and the like, the requirements on the earphones that can be matching with the portable electronics are increasingly higher, the requirements comprise a compact size, and also a Hi-Fi sound quality performance for realistically reproducing a variety of sound effects. In addition, the earphone has become an essential accessory for various electronics in order to enable users to listen to the sound signals provided by electronics without disturbing other peoples, regardless the types of the electronics mentioned above. Furthermore, the earphone also provides a better sound transmission for the listener so that the listener can clearly hear and understand the content of the sound.
The existing earphones can be divided into in-ear earphone, headphone and half-in-ear earphone according to different wearing styles, and mainly comprise an earphone front housing, an earphone rear housing and a loudspeaker unit (a horn) accommodated in the earphone front housing and the rear housing. As different users for earphones have different preferences for the frequency response of the earphone, and for different operating environment, the earphones are required to be adjusted to different frequency response based on individual demands, thus there is an urgent need for an earphone capable of adjusting the frequency response of the earphone based on individual demand so as to adapt to different users and environments.